Temporal remote sensing of thermal diffusion waves in bare soil subsurface at multi-spatial scales
Notice bibliographique
Résumé
There have been several attempts to characterize the soil subsurface such as, locating existing interfaces, buried structures and/or moisture dynamics using remotely sensed data. The aim of this research was to investigate the influence of subsurface soil properties on surface temperature dynamics that could be detected remotely. Achieving this goal requires investigating systematically the problems created by assumptions in the ID model of heat conduction applied to soil profiles at different spatial scales. Investigation at micro scale was conducted by applying a continuous heating test to three samples obtained from Dara Plain, west Gulf of Suez, the Eastern Egyptian Desert, representing the surface crusts formed in Dara plain and Dara dry valley, as well as the hardpan found deep in Dara Plain soil profiles. The results demonstrated that at scales of a few centimeters, the spatial distribution of solid and void phases influenced only the soil bulk thermal properties, but there was no influence on the dynamics of the surface temperature change. This explained the success of fitting the same ID model (R 2=0.99), originally developed to model surface temperature increase of homogenous materials under continuous heating, to observed surface temperature of two soil crusts with different spatial structure as indicated by computed tomography. At the soil profile scale, the surface temperature of a group of synthetic soil profiles with subsurface layers was recorded using a thermal video camera, during a simulated diurnal cycle in the laboratory, while the subsurface thermal property, namely thermal 'inertia' was measured at different depths using heat pulse probes. Results indicated that the presence of subsurface thermal mismatches changed the magnitude and phase of maximum surface temperature with comparison to a dry homogenous sand profile. The increase or decrease in maximum surface temperature depends on the ratio of thermal inertia around mismatch surfaces, as well as direction of thermal gradient field during heating or cooling. Average values of thermal inertia ratios were calculated from heat pulse probe measurements and were used to reconstruct the first harmonic of surface temperature using a theoretical thermal wave model. The model produced delays in timing of the maximum temperature similar to experimental data. Finally, at close-range sensing scale, around 75 m2, principle component analysis was applied to images of infra-red temperatures captured every 1/2 hr during a complete diurnal cycle, for a vineyard in southern Ontario. The results indicate that 45%, 82% and 66% of the variation in surface temperature temporal dynamics during heating, cooling and diurnal cycle, respectively, were attributed to intrinsic subsurface thermal inertia, while 55%, 17% and 34% of surface dynamics were attributed to surface transient effects such as delays induced by orientation of soil surface to solar position. This research concluded that surface conditions, such as microtopography, in an open field situation can interfere with remotely-captured temperature signals related to subsurface characteristics.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».